Setting value of pointer datatype

[jbigot]

In GitLab by @ksiero on Apr 2, 2020, 15:02

With @jbigot we have discussed functionality of setting the pointer datatype value from yaml file. We have several cases of using this feature:

1. Set only the value of the pointer.\ a. NULL pointer value:

metadata:
  pointer_data:
    type: pointer
    subtype: int
plugins:
  set_value:
     on_init:
       - expose:
         - pointer_data: ~

b. copy address from another pointer:

metadata:
  pointer_A: {type: pointer, subtype: int}
  pointer_B: {type: pointer, subtype: int}
plugins:
  set_value:
     on_init:
       - expose:
         - pointer_A: ~ # nullptr
         - pointer_B: $pointer_A  # B points the same place as A

2. Allocate memory and do a shallow/deep copy:

   metadata:
   pointer_A:
   type: pointer
   subtype: 
     type: record
     buffersize: 8
     members:
       pointer_B:
         disp: 0
         type: pointer
         subtype: int
   pointer_B:
   type: pointer
   subtype: 
     type: record
     buffersize: 8
     members:
       pointer_B:
         disp: 0
         type: pointer
         subtype: int
   plugins:
   set_value:
    on_init:
      - expose:
        - pointer_B: 
            allocate: true
            shallow_copy: pointer_A
        - pointer_B: 
            allocate: true
            deep_copy: pointer_A
    on_event:
      some_event:
        - expose:
          - pointer_B: 
              allocate: false
              shallow_copy: pointer_A
          - pointer_B: 
              allocate: false
              deep_copy: pointer_A

3. Just allocate memory.

   metadata:
   pointer_data:
   type: pointer
   subtype: int
   plugins:
   set_value:
    on_init:
       - pointer_data: 
           allocate: true  # just allocate memory

4. Allocate memory and set the values to the subtype.

   metadata:
   scalar_data: int
   pointer_data:
   type: pointer
   subtype: int
   plugins:
   set_value:
    on_init:
       - pointer_data:
           allocate: true         # allocate memory 
           subvalue: $scalar_data # set the value
    on_event:
      some_event:
       - pointer_data:
           allocate: false        # default, memory is allocated
           subvalue: $scalar_data # set the value

   metadata:
   pointer_data:
   type: pointer
   subtype:
     type: array
     size: 4
     subtype: int
   plugins:
   set_value:
    on_init:
       - pointer_data:
           allocate: true         # allocate memory
           subvalue: [0, 0, 0, 0] # set the value
    on_event:
      some_event:
       - pointer_data:
           allocate: false        # default, memory is allocated
           subvalue: [1, 2, 3, 4] # set the value

   metadata:
   pointer_data:
   type: pointer
   subtype:
     type: record
     buffersize: 20
     members:
        member_1:
          disp: 0
          type: int
        member_2:
          disp: 4
          type: array
          size: 4
          subtype: char
   plugins:
   set_value:
    on_init:
      - expose:
        - pointer_data:
           allocate: true  # allocate memory 
           subvalue:       # set the value
             - member_1: 0
             - member_2: "abc"
    on_event:
      some_event:
       - pointer_data:
           allocate: false        # default, memory is allocated
           subvalue:              # set the value
             - member_1: 4
             - member_2: "xyz"

This is my proposition. Any thoughts?

[jbigot]

unassigned @ksiero